1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to image encoding and decoding, and more particularly, to efficiently encoding and decoding an image including a texture region.
2. Description of the Related Art
In a picture, a region regarded as having homogeneousness and a specific pattern such as a unique figure or unique texture is referred to as a texture. A task of extracting statistical features of a texture or dividing a picture into different regions according to disparity in texture is called texture analysis.
In contrast to texture analysis, texture synthesis refers to synthesizing a new texture of a predetermined size from a texture of a small size. Various algorithms for texture synthesis such as “Texture synthesis by non-parametric sampling” by A. A. Efros and T. K. Leung in Proceedings of the Seventh International Conference on Computer Vision, Corfu, Greece, 1999 have been suggested. Using a sample texture of a small size included in a texture region, a texture of a predetermined size, which has the same pattern, i.e., the same figure and texture as those of the sample texture, is synthesized.
FIG. 1 is a view for explaining conventional texture synthesis.
Referring to FIG. 1, using a regular brick-patterned sample texture 110, a brick-patterned texture 120 of a larger size than that of the sample texture 110 is synthesized. As the size of the sample texture 110 increases, the pattern of the synthesized texture 120 may become more similar to that of the sample texture 110.
A texture included in an image degrades the efficiency of image compression. In particular, a texture such as grass or a wave, which is repeated unpredictably, is difficult to predict using interprediction or intraprediction during encoding. In other words, such a texture is not easy to predict using temporal/spatial redundancy in an image, making it difficult to perform compression encoding on the image based on the prediction result.
Therefore, there is a need for an image encoding and decoding method capable of compressing an image with high efficiency using the homogeneousness of a texture region.